U.S. patent number 7,721,729 [Application Number 11/367,856] was granted by the patent office on 2010-05-25 for nebulizing drug delivery device for ventilator.
This patent grant is currently assigned to RIC Investments, LLC. Invention is credited to Eric A. Lieberman, Dirk Von Hollen.
United States Patent |
7,721,729 |
Von Hollen , et al. |
May 25, 2010 |
Nebulizing drug delivery device for ventilator
Abstract
The present invention provides a drug delivery device having a
housing that includes a ventilator interface module and a base
module removeably coupled to the ventilator interface module. An
aerosol generator is disposed in the base module to nebulize a drug
solution provided in the housing. The ventilator interface module
has an outlet port through which nebulized particles of the drug
solution can be communicated to a user, and an inlet port through
which the housing receives intake gas. The housing has a flow path
defined therein that directs intake gas from the inlet port to the
outlet port such that the nebulized drug solution particles formed
in the housing are motivated toward the outlet port when the base
module is coupled to the ventilator interface module. A seal
arrangement substantially seals the inlet port and outlet port from
ambient atmosphere when the base module is uncoupled from the
ventilator interface module, such that intake gas can be
communicated from the inlet port to the outlet port.
Inventors: |
Von Hollen; Dirk (Clark,
NJ), Lieberman; Eric A. (Scotch Plains, NJ) |
Assignee: |
RIC Investments, LLC
(Wilmington, DE)
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Family
ID: |
36969516 |
Appl.
No.: |
11/367,856 |
Filed: |
March 3, 2006 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20060201500 A1 |
Sep 14, 2006 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60659782 |
Mar 9, 2005 |
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Current U.S.
Class: |
128/200.14;
128/203.12; 128/202.27 |
Current CPC
Class: |
A61M
11/002 (20140204); A61M 11/001 (20140204); A61M
11/005 (20130101); A61M 15/0085 (20130101); A61M
2205/3653 (20130101); A61M 16/08 (20130101); A61M
2205/8268 (20130101) |
Current International
Class: |
A61M
11/00 (20060101) |
Field of
Search: |
;128/200.21,200.16,202.27,205.24,203.12,203.15,200.14 ;239/338 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2070062 - RU |
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Dec 1996 |
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RU |
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2076746 - RU |
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Apr 1997 |
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RU |
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WO95/26236 |
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Oct 1995 |
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WO |
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WO 2004/017848 |
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Mar 2004 |
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WO |
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Primary Examiner: Yu; Justine R
Assistant Examiner: Blizzard; Christopher
Attorney, Agent or Firm: Nathan; Timothy A.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 U.S.C. .sctn.119(e) from
provisional U.S. patent application Ser. No. 60/659,782 filed Mar.
9, 2005 the contents of which are incorporated herein by reference.
Claims
What is claimed is:
1. A nebulizing device comprising: a housing, the housing
comprising a ventilator interface module and a base module
removeably coupled to the ventilator interface module; an aerosol
generator disposed in the base module, the aerosol generator
constructed and arranged to nebulize a drug solution provided in
the housing; the ventilator interface module having an outlet port
through which nebulized particles of the drug solution can be
communicated to a user, and having an inlet port through which the
housing receives intake gas; the housing having a flow path defined
therein that directs intake gas from the inlet port to the outlet
port such that the nebulized drug solution particles formed in the
housing are motivated toward the outlet port when the base module
is coupled to the ventilator interface module; a seal arrangement
that substantially seals the inlet port and outlet port from
ambient atmosphere when the base module is uncoupled from the
ventilator interface module, and such that intake gas can be
communicated from the inlet port to the outlet port; and a
separator structure provided in the ventilator interface module
that substantially separates larger solution droplets from
nebulized drug solution particles formed by the aerosol generator,
wherein the separator structure defines a first portion of the flow
path from the inlet port to the outlet port when the base module is
coupled to the ventilator interface module and wherein the first
portion of the flow oath is shaped and positioned to sequentially
direct intake gas from the inlet port, through an aerosol region
that receives drug solution particles nebulized by the aerosol
generator, through the separator structure, and then to the outlet
port such that the intake gas carries the nebulized drug solution
particles from the aerosol region to the separator structure when
the base module is coupled to the ventilator interface module, the
aerosol generator is nebulizing drug solution, and intake air is
flowing through the inlet port.
2. The device of claim 1, further comprising a second portion of
the flow path which bypasses the separator structure when the base
module is coupled to the ventilator interface module, and wherein
the seal structure seals off the first portion of the flow path
from the inlet port and the outlet port when the base module is
decoupled from the ventilator interface module.
3. The device of claim 1 , wherein the separator structure
comprises a return port that returns larger drug solution droplets
to a pool of the drug solution contained in the housing.
4. The device of claim 2, wherein the separator structure comprises
a separator inlet and a separator outlet, and wherein the seal
arrangement comprises engaging surfaces adjacent to the separator
inlet and the separator outlet, and wherein the engaging surfaces
seal the separator inlet and the separator outlet from the inlet
port and the outlet port when the base module is decoupled from the
ventilator interface module.
5. The device of claim 4, wherein the separator structure moves to
cause the engaging surfaces to seal the separator inlet and
separator outlet from the inlet port and the outlet port flow path
when the base module is decouple from the ventilator interface
module.
6. The device of claim 5, further including a spring that biases
the separator structure in a sealing direction, causing the
engaging surfaces to seal the separator inlet and separator outlet
when the base module is decoupled from the ventilator interface
module.
7. The device of claim 6, wherein the separator structure is moved
to an unsealing position, against the bias of the spring, when the
base module and the ventilator interface module are coupled to one
another.
8. The device of claim 1, wherein the flow path directs intake gas
directly from the inlet port to the outlet port when the base
module is uncoupled from the ventilator interface module.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to drug delivery systems, and, in
particular, to nebulizing drug delivery devices used in ventilator
systems.
2. Description of the Related Art
Conventional ventilator drug nebulizers are known in the medical
device industry for use in delivering nebulized particles of a drug
solution to a user. Such devices are typically installed in a
ventilator circuit such that the gas within the ventilator circuit
flows through the nebulizing drug delivery device on its path to
the user. Typically, the drug nebulizer has a sealed housing that
interfaces with the ventilator circuit, and into which a drug
solution is provided. When the drug solution within the drug
nebulizer housing is depleted, the housing must be opened in order
to be replenished with additional drug solution. In some
conventional drug nebulizers, opening the device housing to
replenish the drug solution will result in the ventilator circuit
being exposed to atmospheric air. Such atmospheric air, if
introduced into the ventilator circuit, may be undesirable in
certain instances. In other conventional drug nebulizers, while
atmospheric air may not enter the ventilator circuit to a
significant extent, gas from the ventilator circuit may leak to
atmosphere when the nebulizer housing is opened for replenishing
drug solution. Again, in some instances such leaking of the
ventilator gas flow to atmosphere may be undesirable.
SUMMARY OF THE INVENTION
In accordance with the broad teachings of the invention, one aspect
of the invention relates to a nebulizing device comprising a
housing that includes a ventilator interface module and a base
module removeably coupled to the ventilator interface module. An
aerosol generator is disposed in the base module and is constructed
and arranged to nebulize a drug solution provided in the housing.
The ventilator interface module has an outlet port through which
nebulized particles of the drug solution can be communicated to a
user, and has an inlet port through which the housing receives
intake gas. The housing has a flow path defined therein that
directs intake gas from the inlet port to the outlet port such that
the nebulized drug solution particles formed in the housing are
motivated toward the outlet port when the base module is coupled to
the ventilator interface module. A seal arrangement substantially
seals the inlet port and outlet port from ambient atmosphere when
the base module is uncoupled from the ventilator interface module,
such that intake gas can be communicated from the inlet port to the
outlet port.
In one embodiment, the device may comprise a separator structure
provided in the ventilator interface module that substantially
separates larger drug solution droplets from nebulized drug
solution particles formed by the aerosol generator.
In another embodiment, the flow path directs intake gas directly
from the inlet port to the outlet port so as to bypass a separator
structure when the base module is uncoupled from the ventilator
interface module.
These and other objects, features, and characteristics of the
present invention, as well as the methods of operation and
functions of the related elements of structure and the combination
of parts and economies of manufacture, will become more apparent
upon consideration of the following description and the appended
claims with reference to the accompanying drawings, all of which
form a part of this specification, wherein like reference numerals
designate corresponding parts in the various figures. It is to be
expressly understood, however, that the drawings are for the
purpose of illustration and description only and are not intended
as a definition of the limits of the invention. As used in the
specification and in the claims, the singular form of "a", "an",
and "the" include plural referents unless the context clearly
dictates otherwise.
BRIEF DESCRIPTION OF THE DRAWINGS
A specific embodiment of the invention is now described with
reference to the accompanying drawings, wherein:
FIG. 1 illustrates a perspective view of the nebulizing device in
accordance with an embodiment of the invention.
FIGS. 2A-2C illustrate elevational views of a first side, an inlet
end, and an outlet end of the nebulizing device in accordance with
an embodiment of the invention.
FIG. 3 is an exploded perspective view that illustrates a
ventilator interface module and a base module of the nebulizing
device arranged in an uncouple position, according to one
embodiment of the invention.
FIG. 4 illustrates an exploded sectional view of the nebulizing
device of FIG. 2C, taken along section line 4-4, according to one
embodiment of the invention, but showing the base module separated
from the ventilator interface module.
FIG. 5 illustrates a sectional view of the nebulizing device
similar to FIG. 4, but showing the base module coupled to the
ventilator interface module.
FIGS. 6A and 6B are lower plan views of the nebulizing drug
delivery device, in accordance with an embodiment of the
invention.
FIG. 7 is a cross-sectional view of the nebulizing device similar
to FIG. 5, but illustrating the operation of the nebulizing drug
delivery device, in accordance with one embodiment of the
invention.
FIG. 8 is a cross-sectional view of the nebulizing device similar
to FIG. 4, but illustrating the ventilator flow path after the base
module has been decoupled to the ventilator interface module.
FIG. 9 illustrates a sectional view of an alternate embodiment of
the nebulizing drug of the invention that does not employ a guide
tube arrangement.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS OF THE
INVENTION
FIGS. 1 and 2A-2C are exemplary illustrations of an in-line
nebulizing device 10 in accordance with the present invention.
Device 10 includes a housing 12 comprising a ventilator interface
module 14 and a base module 16. Ventilator interface module 14
includes an upper ventilator interface housing 18 and a lower
ventilator interface housing 20. The base module 16 has an outer
housing 21. As is illustrated in FIGS. 2B and 2C, upper ventilator
interface housing 18 and lower ventilator interface housing 20 are
coupled together via a first fastener 22 on a first side of housing
12 and a second fastener 24 on a second side of housing 12. The
first fastener 22 extends through openings formed through
projections 26, 28 disposed at a lower end of the upper ventilator
interface housing 18 and upper end of lower ventilator interface
housing 20, respectively. In other embodiments, upper ventilator
interface housing 18 and lower ventilator interface housing 20 may
be securely coupled via one or more of a weld, an adhesive bond, a
snap-fit, or other mechanisms for securely coupling components.
Referring to FIGS. 1 and 2A, ventilator interface module 14
includes a gas inlet port 30 at inlet portion 32 of device 10 and a
gas outlet port 34 at outlet portion 36 of device 10. Inlet port 30
is formed by a hollow tubular inlet port wall 38 that extends
outwardly from ventilator interface module 14. Outlet port 34 is
formed by a hollow tubular outlet port wall 40 that extends
outwardly from ventilator interface module 14 in an opposite
direction from the inlet port 30. As is illustrated in FIGS. 2B and
2C, tubular inlet port wall 38 and tubular outlet port wall 40 may
be cylindrical in shape, but other tubular conduit configurations
may alternately be employed.
As illustrated in FIG. 3, the ventilator interface module 14 and
base module 16 can be manually coupled and decoupled from one
another. More particularly, the outer housing 21 has opposite,
generally flat and parallel upstanding wall portions 42. The
generally parallel wall portions are connected at opposite ends
thereof by outwardly projecting curved wall portions 44. The upper
ends of the curved wall portions 44 have respective arcuate
channels 46 and 48 formed therein as shown in FIG. 3 and the
cross-sectional view of FIG. 4. As can also be appreciated from
FIG. 4, the lower portion of lower ventilator interface housing 20
has projecting barb regions 50 and 52, which are configured to be
received in the channels 46 and 48, respectively, for coupling and
decoupling the ventilator interface module 14 to the base module 16
as will be described in greater detail below.
In general, it should be appreciated that the ventilator interface
module 14 is adapted to be connected with a ventilator line.
Specifically, the inlet port 30 is adapted to be connected with the
output tubing of a ventilator system, and the outlet port 34 is
adapted to be connected with tubing that will communicate
aerosolized drug particles to a user. The ventilator interface
module 14 contains a separator structure 56 disposed within the
flow path between the inlet port 30 and outlet port 34. The
separator structure 56 provides a circuitous flow path within the
ventilator interface module that causes the larger droplets of drug
solution to remain within the housing 12, while permitting the
smaller nebulized particles to exit through the outlet port 34. As
will be described in more detail later, ventilator interface module
14 advantageously provides an internal structural arrangement that
will generate a direct flow path from inlet port 30 to the outlet
port 34, thus bypassing the flow path region within the separator
structure 56 when the base module 16 is decoupled from the
ventilator interface module 14. As a result, the inlet port 30 and
outlet port 34 remain sealed from atmosphere even when the base
module 16 is decoupled. In addition, gas can continue to flow from
the tubing connected to the inlet 30 to the tubing connected with
the outlet 34 even when the base module 16 is decoupled. As will be
described, in one embodiment, this is accomplished by sealing off
the separator structure region of the flow path.
It will also be appreciated that, in general, the base module 16
includes a drug solution container 60 for containing the drug
solution to be nebulized. A pool of drug solution 62 (e.g., see
FIG. 7) can be provided into the container 60. In one embodiment,
the pool of drug solution 62 is a metered dose of drug solution
provided into the container 60 by the operator of device 10. The
base module 16 also contains an aerosol generator 66 that can be
operated to generate nebulized particles of drug solution from the
drug solution 62 provided in the container 60, as will be described
in greater detail later. It should be appreciated that many
different types of aerosol generators are known and may be used in
accordance with the principle of the present invention. In one
embodiment, the aerosol generator 66 comprises a concave shaped
piezoelectric transducer that communicates acoustic waves to the
drug solution 62 through an acoustic wave transmitting fluid 70
(see FIG. 7). The fluid 70 is separated from the drug solution 62
by a barrier member 412, as will be described later. Other
structural and functional characteristics of aerosol generators
that may be used are described in PCT application no.
PCT/AU2003/001079 (International Publication No. 2004/017848) which
is hereby incorporated by reference. In addition, various other
aerosol generators could be utilized without departing from the
unique aspects of the present invention. The aerosol generator may
include any contemporary aerosol generator such as nebulizers that
utilize a planar transducer, a vibrating mesh, vibrating plate,
electro spray to generate an aerosol.
FIG. 5. is a cross-sectional view of an embodiment device 10, taken
along cross-section line 4-4 in FIG. 2C. As shown, lower ventilator
interface housing 20 includes a lower ventilator interface outer
member 310, a guide channel member 312, and a channel support 314.
Lower ventilator interface outer member 310 provides an outer
surface of lower ventilator interface housing 20. Guide channel
member 312 forms a guide channel 316 in a longitudinal direction
within a central region of ventilator interface module 14. Guide
channel member 312, includes a channel sealing surface 318 at an
upper end of guide channel 316. Channel support 314 is disposed
between guide channel member 312 and lower ventilator interface
outer member 310, and provides a structural connection between
guide channel member 312 and lower ventilator interface outer
member 310. Channel support 314 includes an upper ventilator
interface housing seating surface 320.
Upper ventilator interface housing 18 has an opening defined by an
interface housing rim 324. Upper ventilator interface housing
opening defined by rim 324 is adapted to receive the separator
structure 56 and other structural portions of the lower ventilator
housing 20 when the upper and lower portions 18, 20 of the
ventilator housing are secured together. In addition, when upper
ventilator interface housing 18 and lower ventilator interface
housing 20 are coupled (for example, by first fastener 22 and
second fastener 24) an upper portion of guide channel member 312 is
received into housing 18 via the opening defined by rim 324, and
the rim 324 sits in contact with the ventilatory interface housing
320 provided on the lower ventilator housing portion 20.
The upper wall 322 of the upper ventilator interface housing 18 and
the upper exterior surfaces 361 of the separator structure 56
generally define a fluid bypass passage 362. The bypass passage 362
provides for fluid communication directly from the inlet port 30 to
the outlet port 34, bypassing the internal portions of the
separator structure 56.
Upper wall 322 of the ventilator interface housing 18 includes a
spring seating structure 328. Spring seating member 328 is adapted
to retain a spring 330 at a first end of spring 330. The spring 330
extends through the fluid bypass passage 362 and has a second end
thereof engaging an upper planar region 340 of the separator
structure 56.
As shown, separator structure 56 includes a separator inlet region
334, a first aerosol region 336, a second aerosol region 338, and a
planar separator member 340. Separator inlet region 334 is defined
by an outer separator wall 342, a first inner separator wall 344,
planar separator member 340, and a separator inlet region opening
346. A separator inlet 348 permits fluid to be introduced into
separator inlet region 334, which in turn allow fluid to be
transmitted to the first aerosol region 336 through an opening or
inlet 352 into the first aerosol region 336. Separator structure 56
is rotationally oriented within guide channel 316 such that
separator inlet 348 is aligned with inlet port 30, as is shown in
FIG. 2C.
First aerosol region 336 is generally defined by aerosol region
ceiling 350, first inner separator wall 344, inlet 352, second
inner separator wall 354, and an aerosol region passage 356 formed
by second inner separator wall 354 and aerosol region ceiling
350.
Second aerosol region 338 is defined by aerosol region ceiling 350,
aerosol region passage 356, a drug return 358, and outer separator
wall 342. Drug return 358 is disposed in a lower portion of second
aerosol region 338, and includes a drug return opening 359. A
separator outlet 360 is formed in outer separator wall 342 that
enables communication between second aerosol region 338 and outlet
port 34. Separator outlet 360 is formed in outer separator wall 342
such that when separator inlet 348 is aligned with inlet port 30,
separator outlet 360 is aligned with outlet port 34, as is shown in
FIG. 2B.
Planar separator member 340 extends outward from separator
structure 334 to form a protruding separator rim 362. Protruding
separator rim 362 provides a separator sealing surface 364 that
faces channel sealing surface 318.
Ventilator interface module 14 includes a guide tube 366. A first
end of guide tube 366 extends into first aerosol region 336 and a
second end of guide tube 366 extends out of aerosol region 336 into
a drug solution container 60 associated with base module 16. Guide
tube 366 is held in structural connectivity with separator
structure 56 by a guide tube collar 370. Guide tube collar 370 is
connected to separator structure 56 adjacent aerosol region inlet
352 by collar struts 372. Inlet openings 352 to provide
communication between first aerosol region 336 and drug solution
container 60.
According to various embodiments of the invention, base module 16
includes outer housing 21, an aerosol generator housing 376, a drug
pool housing 378, and control electronics 380. Outer housing 21
forms a cavity 381 in which aerosol generator housing 376, a
portion of drug pool housing 378, and control electronics 380
reside. A power connection opening 382 is provided in outer housing
21 to receive a power connector from an external power source. In
other embodiments, device 10 may be powered by an internal power
source, such as a battery, a fuel cell, or other internal power
sources.
In one embodiment, aerosol generator housing 376 includes aerosol
generator seating portion 384, and a rim portion 386. Drug pool
housing 378 includes drug solution container 60, a barrier opening
388, a lower skirt portion 390, and a drug pool housing support
392.
An aerosol generator 66 is mounted within aerosol generator housing
376 at aerosol generator seating portion 384. As noted above, in
one embodiment, and as illustrated, aerosol generator 66 comprises
an acoustic wave aerosol generator that generates acoustic waves
within device 10. In the embodiment illustrated in FIG. 5, and as
stated above, the aerosol generator 66 comprises a concave
piezoelectric transducer with a silver electrode. The piezoelectric
transducer generates acoustic waves at a generator frequency, such
as, in a non-limiting example, 2.5 MHz. The acoustic waves are
focused by the concave configuration of the piezoelectric
transducer at a focal point that is at a focal length from aerosol
generator 66. Device 10 is arranged such that the focal point falls
within drug solution container 60.
Aerosol generator housing 376 and drug pool housing 378 may be
joined such that rim portion 386 of aerosol generator housing 376
and lower skirt portion 390 of drug pool housing 378 define a
transmitting fluid chamber 396, positioned beneath drug solution
container 60. Rim portion 386 and lower skirt portion 390 may be
securely joined via one or more of a weld, an adhesive bond, a
fastener, a snap-fit, or other mechanisms for securely joining
components.
In some embodiments, drug solution container 60, disposed within
drug pool housing 378, is formed by a chamber wall 398 and a
chamber floor 410. Chamber floor 410 slopes in a downward direction
from chamber wall 398 to barrier opening 388, formed in chamber
floor 410. Barrier opening 388 provides a pathway between
transmitting fluid chamber 396 and drug solution container 60
through which acoustic waves may be communicated.
Although acoustic waves may be transmitted through barrier opening,
a barrier 412 is provided at barrier opening 388 to prevent fluid
communication between transmitting fluid chamber 396 and drug
solution container 60. Barrier 412 is mounted across barrier
opening 388 at a barrier mounting surface 414. In the embodiment
shown, barrier mounting surface 414 is illustrated as being
provided at an upper surface of transmitting fluid chamber 396, but
alternate configurations exist. For example, barrier mounting
surface 414 may be provided at chamber floor 410, or otherwise
located. Barrier 412 may be composed of one or more materials that
meets various design criteria. Design criteria may include, for
example, a prescribed thickness, an elasticity, a durability at
high temperatures, an acoustic wave transmission property, or other
criteria.
It will be appreciated that ventilator interface module 14 and base
module 16 may be formed as an integral housing, or may be securely
joined to form a single unitary (or substantially unitary) housing.
However, in the embodiments illustrated, ventilator interface
module 14 and base module 16 are selectively coupled at a housing
interface 416. As seen in FIGS. 2B, 2C, 4, and 5, at housing
interface 416, ventilator interface module 14 provides a first
barbed overlap 50 and a second barbed regions 52 that extend down
from ventilator interface module 14. Referring to FIG. 4, first and
second barbed overlaps 50 and 52 include a first overlap barb 422
and a second overlap barb 424, respectively, at inner surfaces of
barbed overlaps 50 and 52. A first barb slot 426 is formed in first
overlap barb 422, and a second barb slot 428 is formed in second
overlap barb 424. Barb slots 426 and 428 are formed in overlap
barbs 422 and 424 at central regions of inlet end 32 and outlet end
34 of device 10.
At housing interface 416, base module 16 provides a first interface
channel 46 and a second interface channel 48. As is shown in FIG.
3, interface channels 48 and 432 run along the base module 16, the
length of inlet end 32 and outlet end 34, respectively. Referring
back to FIG. 4, a first biased tab 434 and a second biased tab 436
are provided by base module 16 at housing interface 416. A first
tab barb 438 and a second tab barb 440 are disposed on first biased
tab 434 and second biased tab, respectively. Biased tabs 434 and
436 are provided by base module 16 such that an upper portion of
biased tabs 434 and 436 are arranged within interface channels 46
and 48. As is illustrated in FIG. 3, biased tabs 434 and 436 are
provided by base module 16 at the central regions of inlet end 32
and outlet end 34, such that when ventilator interface module 14
and base module 16 are coupled, tab barbs 438 and 440, disposed on
biased tabs 434 and 436, align with barb slots 426 and 428, as
shown in FIG. 5.
Still referring to FIG. 5, when ventilator interface module 14 is
coupled to base module 16, drug solution container 60 of drug pool
housing 378 is received into guide channel 316. When drug solution
container 60 is received into guide channel 316, an upper edge of
chamber wall 398 interfaces with a lower edge of outer separator
wall 342. Outer separator wall 342 is maintained in contact with
chamber wall 398 by virtue of a downward bias applied to separator
structure 56 by spring 330 at a separator spring surface 442,
provided by planar separator member 340.
Turning to FIG. 4, when ventilator interface module 14 is uncoupled
from base module 16, drug solution container 60 is withdrawn from
guide channel 316, which removes chamber wall 398 from contact with
outer separator wall 342. In the absence of this contact, the bias
applied by spring 330 forces separator structure 56 to slide
downwardly within guide channel 316 until separator inlet 348 and
separator outlet 360 drop below channel sealing surface 318 of
guide channel 316, thus sealing inlet separation 348 and outlet 360
of the separator structure 56 from inlet 30 and outlet 34. In
addition, separator sealing surface 364 engages channel sealing
surface 318. The engagement between separator sealing surface 364
and channel sealing surface 318 forms a seal arrangement 444 that
seals the internal passage of the separator structure from the flow
bypass cavity 326. This retains sealed communication from the inlet
port 30 to the outlet port 34 through the flow bypass cavity 326,
without leakage to or from ambient air.
In the illustrated embodiment, spring 330 is a compressible coil
spring. It should be appreciated, however, that spring 330 is
merely one example of a device capable of biasing. Springs of many
different types could be employed to generate the sealing action,
such as leaf springs, torsion springs, or resilient biasing
materials. In addition, one of ordinary skill in the art can best
appreciate that various other biasing mechanisms other than springs
could be used to bias separator structure 56 such as properly
aligned magnets (including permanent magnets and electromagnets),
or shape memory alloys, and the like.
In addition, other structures for the sealing arrangement 444 can
be used. For example, in one embodiment, the sealing arrangement
includes an electric or pneumatically operated actuator rather than
a spring to moves the separator structure 56 downwardly to create a
sealed passage from the inlet port 30 to the outlet port 34 when
the base module 16 is removed. In this arrangement, various
mechanism can be used to detect that the base module 16 has been
decoupled from the ventilator interface module 14. For example, in
one contemplated configuration, a light-pipe detector circuit would
be carried by the ventilator interface module 14. The light pipe
detector circuit can detect when the base module 16 has been
decoupled as a result of a conduit between a signal transmitter
output and a signal receiver input being disrupted. Further details
of such an arrangement, and other arrangements for detecting that
the base module 16 has been decoupled will be appreciated from
co-pending U.S. Application Ser. No. 60/659,778, entitled
NEBULIZING DRUG DELIVERY DEVICE WITH INTERLOCK AND DETECTION AND
TEMPERATURE PROTECTION, and from co-pending U.S. application Ser.
No. 60/659,781 entitled NEBULIZING DRUG DELIVERY DEVICE WITH
BARRIER, each of which is filed on even date herewith and hereby
incorporated by reference in its entirety. It is further
contemplated that such a detection circuit can alternatively, or in
addition, be carried by base module 16 and used to disable the
aerosol generator 66 when base module 16 has been decoupled from
the ventilator interface module 14, as can also be appreciated from
the aforementioned co-pending U.S. Applications.
In another contemplated embodiment, the separator structure 56 can
remain stationary, and the sealing arrangement 444 can take the
form of one or more valves that create a sealed passage from the
inlet port 30 to the outlet port 34 when the base module 16 is
decoupled from the ventilator interface module. This can be
accomplished by having a pair of valves (such as solenoid valves)
seal separator inlet 348 and separator outlet 360 when a detector
detects that the base module 16 has been decoupled. Thus, flow from
inlet 30 will only travel through the bypass passage to the outlet
port 34 and bypass the separator structure 56.
In yet another embodiment, it is contemplated that valves can be
provided at the separator inlet region opening 346 and drug return
opening 359. In this arrangement, fluid would be permitted to pass
through not only the bypass passage cavity 326, but also pass
through the internal regions 334, 336, 356 of the separator
structure 56 before exiting the outlet port 34.
In the disclosed embodiments, when the base module 16 is uncoupled
from the ventilator interface module 14, the inlet port 30 and
outlet port 34 are substantially sealed from ambient atmosphere. As
a result, intake gas from a ventilator can be communicated from the
inlet port to the outlet port without leaking to atmosphere. In
addition, atmospheric air does not leak into the flow path from the
inlet port 30 to the outlet port 34, when the base module is
removed.
Ventilator interface module 14 may be coupled to base module 16 by
first, placing modules 14 and 16 in the position shown in FIG. 3.
This includes positioning the uncoupled modules 14 and 16 so that
while chamber wall 398 of base module 16 and guide channel 316 of
ventilator interface module 14 are aligned along a common axis,
ventilator interface module 14 and base module 16 are oriented in
transverse directions. After positioning modules 14 and 16 in this
manner, they are moved relative to each other along the common axis
to introduce drug solution container 60 into guide channel 316.
In this position, ventilator interface module 14 and base module 16
will be in contact with each other and will be in the position
illustrated in the lower elevation view provided by FIG. 6A.
Ventilator interface module 14 and base module 16 are then rotated
with respect to each other to bring modules 14 and 16 into the
position shown in the lower elevation view of FIG. 6B. Rotating
ventilator interface module 14 and base module 16 will introduce
first overlap barb 422 and second overlap barb 424 into first
interface channel 46 and second interface channel 48, respectively.
By continuing to rotate modules 14 and 16, overlap barbs 422 and
424 will be slid into interface channels 46 and 48 to couple
ventilator interface module 14 to base module 16. When first
overlap barb 422 and second overlap barb 424 contact, and slide
along, first biased tab 434 and second biased tab 436, biased tabs
434 and 436 will be deformed inwardly into interface channels 46
and 48. As modules 14 and 16 are rotated to the alignment
illustrated in FIG. 6B, first tab barb 438 and second tab barb 440
will be received into first barb slot 426 and second barb slot 428,
respectively, as is illustrated in FIG. 5. Due to the outward bias
of biased tabs 434 and 436 caused by deforming biased tabs 434 and
436 in an inward direction, tab barbs 438 and 440 will engage barb
slots 426 and 428 to rotationally secure overlap barbs 422 and 424
within interface channels 46 and 48.
To uncouple the coupled modules 14 and 16, first biased tab 434 and
second biased tab 436 can be deformed inwardly by applying an
inward force at a first depressible surface 446 and a second
depressible surface 448 provided on first biased tab 434 and second
biased tab 436, respectively. Depressible surfaces are illustrated
in FIGS. 1, 2A, 2B, 3, 4, and 5. Deforming biased tabs 434 and 436
disengages tab barbs 438 and 440 from barb slots 426 and 428,
thereby enabling ventilator interface module 14 and base module 16
to be rotated to remove overlap barbs 422 and 424 from interface
channels 46 and 48.
FIG. 7 is an exemplary cross-sectional view of an embodiment of
device 10 during use, taken along cross-section line 3. As will be
described in greater detail below, the ventilator interface module
14 generally functions to deliver nebulized drug solution particles
to a user through outlet port 34. Intake gas is received into
housing 12 through inlet port 30. Prior to delivery of the
nebulized drug solution particles, the internal structure of
ventilator interface module 14 separates larger drug solution
droplets from the nebulized particles that are delivered to the
user and returns such larger droplets to the drug solution 62
within container 60.
As illustrated in the cross-section of FIG. 7, the nebulized
particles of the drug solution are formed in device 10 from drug
solution forming the drug solution 62 held within housing 12 at
drug solution container 60, which sits over aerosol generator 66.
More specifically, acoustic waves are transmitted from aerosol
generator 66 to the drug solution 62 via an acoustic wave
transmitting fluid 70 held within transmitting fluid chamber 396.
Acoustic waves are transmitted from the acoustic wave transmitting
fluid 70 to the drug solution 62 via barrier 412.
In one embodiment, the transmitting fluid 70 may primarily be
comprised of water. In some instances, a sterilant, such as
alcohol, or another sterilant, may be added to the acoustic wave
transmitting fluid 70.
As was set forth previously, the acoustic waves generated by
aerosol generator 66 are focused at a focal point within the drug
solution 62 formed in drug solution container 60. The drug solution
present at the focal point of the acoustic waves will absorb the
ultrasonic energy to create a fountain 710 from the drug solution
62. That is, the focused acoustic waves will generate a focused
stream of the drug solution, which stream begins at a point that
can also be considered the beginning of fountain 710. Towards the
top of the stream or fountain 710, the energized drug solution
within the drug solution 62 is nebulized to form aerosol drug
solution particles. Some of the drug solution in fountain 710 may
not be nebulized, but rather form larger droplets of the drug
solution that will be returned to the drug solution 62.
In some embodiments of the invention, the nebulization of the drug
solution at fountain 710 may be enhanced when the focal point of
the acoustic waves coincides (exactly or substantially) with a
surface 712 of the drug solution in drug solution container 60. In
such embodiments, the level of surface 712 may be controlled with
some particularity to enhance the operation of fountain 710.
According to some embodiments of the invention, and as previously
mentioned, guide tube 366 may be disposed within device 10 such
that a first end is positioned in first aerosol region 336, and a
second end of guide tube 366 that extends into the drug solution 62
formed in drug solution container 60, over barrier 412. In such
instances, fountain 710 can be formed within guide tube 366 as a
result of the focal point being disposed proximate the second end
of guide tube 366. Drug solution from the drug solution 62 may be
propelled toward the first end of guide tube 366 by the ultrasonic
energy from the acoustic waves. At the first end of guide tube 366,
the energized drug solution stream exits guide tube 366. Nebulized
(or aerosolized) particles of the drug solution are formed towards
the upper portions of the steam or fountain 710 of drug solution.
Guide tube 366 may increase the formation of the nebulized
particles of the drug solution within fountain 710 by itself
functioning to energize drug solution within guide tube 366 that is
not be located at the focal point of the acoustic waves.
Continuing with reference to FIG. 7, the nebulized particles pass
through device 10, from the drug solution 62 to outlet port 34, via
separator structure 56. More particularly, the nebulized particles
are received from guide tube 366 into first aerosol region 336,
pass into second aerosol region 338, and are communicated to outlet
port 34 through separator outlet 360. The nebulized particles are
communicated between first aerosol region 336 and second aerosol
region 338 via aerosol region passage 356. The various components
of separator structure 56 may be arranged such that the nebulized
particles may pass through to outlet port 34, while the larger
droplets of the drug solution may, due to size and/or weight,
contact surfaces of separator structure 56, such as first inner
separator wall 344, second inner separator wall 354, aerosol region
ceiling 350, or outer separator wall 342 and condense on the
contacted surface. The drug solution included in the larger
particles that condenses on separator structure surfaces in second
aerosol region 338 will be returned to the drug solution 62 via
second aerosol region 338. The drug solution included in the larger
particles that condense on separator structure surfaces in first
aerosol region 336 will return to the drug solution 62 through
aerosol region inlet 352.
At inlet port 30, intake gas is received by device 10. A flow path
may be established between inlet port 30 and outlet port 34 that,
when ventilator interface module 14 is coupled to base module 16,
directs at least a portion of the intake gas such that the intake
gas motivates the nebulized particles from fountain 710, through
separator structure 56, to outlet port 34.
Referring again to FIG. 7, intake gas directed into separator
structure 56 via separator inlet 348 flows through separator inlet
region 334 and into container 60. The intake gas provided to drug
solution container 60 may enter first aerosol region 336 at aerosol
region inlet 352 and flow through separation inlet region 334 and
first aerosol region 336 to separator outlet 360 where it will be
communicated to outlet port 34. The nebulized particles formed at
fountain 710 may be motivated by the flow of the intake gas along
the flow path as the intake gas passes fountain 710 at aerosol
region inlet 352 and proceeds toward outlet port 34. Intake gas
that does not enter separator structure 56 passes directly from
inlet port 30 to outlet port 34 through flow bypass cavity 326.
When ventilator interface module 14 and base module 16 are
uncoupled, as is illustrated in FIG. 8, sealing arrangement 444
seals the flow path from inlet port 30 to outlet port 34 by sealing
flow bypass cavity 326, as has been described above. For example,
the intake gas may include filtered gas provided to device 10 in a
force flow along a ventilator circuit. The ventilator circuit may
provide the intake gas through an operative connection at inlet
port 30, and may receive the output of device 10 via an operative
connection with outlet port 34. Sealing the flow path when modules
14 and 16 are uncoupled may inhibit contamination of the intake gas
in the ventilator circuit.
In one embodiment of the invention, as seen most clearly in FIGS.
7, and 8, a variable volume resilient structure 714 is disposed
within transmitting fluid chamber 396 and is in contact with the
fluid 70 held therein. Resilient structure 714 may be reduced in
volume so as to reduce the amount of space it occupies in
transmitting fluid chamber 396. In one embodiment, resilient
structure 714 is composed of a deformable material to accommodate
expansions in the volume of the fluid 70, and thereby protect other
components from damage due to changes in the volume. For instance,
aerosol generator 66, barrier 412, may potentially be subject to
damage in the event that ambient temperature surrounding device 10
is low enough to cause a fluid temperature of the fluid 70 to
approach or reach freezing. Or, the fluid 70 may also expand as the
fluid temperature rises. In the event of such expansion of the
transmitting fluid 70, resilient structure 714 will reduce in
volume to accommodate the increased volume of the fluid. This, for
example, may prevent cracking of the transmitting fluid chamber
396.
In the figures, resilient structure 714 is illustrated in an
exemplary manner as a bladder. Expansion protection bladder 714 is
composed of a deformable material, such as, for instance, silicon,
or other deformable materials. Bladder 714 has an opening 716
peripherally sealed to an opening in a lower surface of
transmitting fluid chamber 396. Opening 716 leads into an internal
space in the bladder 714 that is exposed to atmosphere. Bladder 714
may be vented to atmosphere via a passage 716 that leads to an open
space 718 in housing 12. Space 718 is not sealed, and is allowed to
bleed air and receive air to and from atmosphere. Because the
amount of air displaced is small and only needs to be done over a
long period of time, there is no need for a large vent housing 12
for this purpose, as the slow permeation of air to and from space
718 is sufficient.
It is contemplated that resilient structure 714 can be formed from
different materials, or from a plurality of different members. For
example, the resilient structure can be made from a sponge
material. In another embodiment, resilient structure 714 may
include a rigid structure that is biased into transmitting fluid
chamber 396 by a spring or other resilient member. The rigid
structure would form a moving seal with transmitting fluid chamber
396 and take up more or less of the chamber volume based on the
fluid volume as described above.
According to one embodiment of the invention, an inner diameter of
guide tube 366 may be varied to provide control over one or more
aspects of the nebulization of the drug solution. For instance, by
varying the inner diameter of guide tube 366, a nebulized particle
size delivered to the user, a flow rate of the drug solution
delivered to the user, or other aspects of the nebulization may be
controlled. In a non-limiting example, guide tube 366 may include
an inner diameter of between 2 mm and 3 mm, with smaller inner
diameters producing smaller nebulized particles and/or a lower flow
rate, and larger inner diameters producing larger nebulized
particles and/or a higher flow rate.
It should be appreciated that many of the principles and features
described herein can be used in an embodiment of the present
invention that does not employ guide tube 366. In such a system,
most of the volume of drug solution within device 10 is contained
in a reservoir that feeds the drug solution to the drug solution 62
that rests on the barrier 412 as the drug solution pool becomes
depleted. A valve system, such as a float valve, can be used to
regulate or control distribution of the drug solution from the drug
solution pool to the barrier 412.
More particularly, in one embodiment illustrated in FIG. 9, a drug
reservoir 910 may provide the drug solution to the drug solution 62
held in container 60 via a fill channel 912 to replenish the drug
solution when the level of surface 712 of the drug solution drops
due to nebulization, or other factors, thereby maintaining the
level of surface 712 of the drug solution 62 at or proximate to the
focal point of the acoustic waves generated by aerosol generator
66.
A float valve 914 may be positioned at a fill channel opening 916
in drug solution container 60 such that when the level of surface
712 rises, float 914, which is buoyant in the drug solution, rises
up to block the drug solution from flowing into drug solution
container 60 from fill channel 912. However, when the level of
surface 712 begins to drop, float valve 914 falls away from fill
channel opening 916, thereby enabling the drug solution in fill
channel 912 to flow into drug solution container 60 until the level
of surface 712 rises to a point where float 914 again blocks fill
channel opening 916. Float valve 914 may include a ball float, or
float valves of other shapes.
The large droplets of the drug solution formed at fountain 710 are
separated from the nebulized particles of the drug solution formed
at fountain 710 by separator structure 56. Subsequent to
separation, the large droplets are returned to drug solution
reservoir 910 via drug return 358.
In some embodiments of the invention, separator structure 56 may
provide a drug delivery path from fountain 710 to outlet port 34
for the nebulized particles formed at fountain 710. As the
nebulized particles travel along the drug delivery path, separator
structure 56 provides surfaces that separate nebulized particles
formed at fountain 710 from the larger droplets formed by the drug
solution propelled out of the drug solution 62 prior to delivery of
the nebulized particles to the user. Subsequent to separation from
the nebulized particles, the larger droplets are returned to drug
reservoir 910 and/or the drug solution 62.
This arrangement is disclosed more fully in co-pending U.S. patent
application Ser. No. 60/659,919 entitled NEBULIZING DRUG DELIVERY
DEVICE WITH INCREASED FLOW RATE, filed on even date herewith and
hereby incorporated by reference in its entirety.
Returning to FIG. 7, an optional embodiment of device 10 that
includes a drug solution detection system 720 is illustrated. Drug
solution detection system 720 detects if the amount drug solution
within the drug solution 62 falls below a threshold level based on
detection of an AC electrical signal generated by aerosol generator
66. Drug solution detection system may include a probe 722, and a
signal lead 724.
Probe 722 is positioned to detect the AC signal generated by
aerosol generator 66 via the drug solution 62. In other words, the
drug solution itself may act as a conduit for the AC signal that
conducts the AC signal to probe 722. When surface 710 of the drug
solution 62 falls below the threshold level, the drug solution will
no longer be able to deliver the AC signal to probe 722. Although
probe 722 is illustrated as being disposed within the drug solution
62, detecting the AC signal directly, in other embodiments, probe
722 may be disposed in contact with an outer surface of chamber
wall 398 and may detect the AC signal capacitively through the
wall.
The AC signal (or lack thereof) detected by probe 722 may be
relayed to control electronics 380 via signal lead 724.
In one embodiment, when the AC signal is not detected, control
electronics 380 may automatically deactivate device 10. For
example, aerosol generator 66 may be deactivated. Or, control
electronics 380 may activate an alert, such as, for example, a
visual or audible indicia, that may warn the user that level 710 of
the drug solution may have dropped below the threshold level.
The threshold level as contemplated herein can be virtually
"empty". However, it may be desirable for the threshold level to be
some drug solution volume above empty, to allow the user sufficient
warning that the drug solution is near depletion. In addition, when
the drug solution volume reaches below a certain level, its thermal
mass also drops below a threshold that may make it more susceptible
to temperature changes in the environment or due to components
within the device itself. Such temperature changes may be
undesirable, as it may alter the effectiveness of certain drug
solutions. In one non-limiting example, it may be desirable in some
embodiments of the present invention to provide the device 10 with
a heater that heats the drug solution 62. Such a heating
arrangement may be desirable to lower the viscosity of the drug
solution 62, particularly when using a drug solution of a high
viscosity. Such a heater may be provided in contact with the drug
solution 62 itself, or surrounding drug solution container 60, as
described in the aforementioned co-pending U.S. patent application
Ser. No. 60/659,919 entitled NEBULIZING DRUG DELIVERY DEVICE WITH
INCREASED FLOW RATE, which is incorporated by reference in its
entirety. In the event that the amount of drug solution drops below
a threshold level, the thermal mass of the drug solution 62 may be
subject to over heating. This may prevented by disabling the
aerosol generator 66 through use of control electronics 380 when
the amount of drug solution drops below a threshold level as
described above.
In another embodiment, it is contemplated two different drug
solution levels may be detected. In such a system, a first low
level is detected and provides either an audible or visual alarm to
the user. This may prompt the user to refill the device 10 with
drug solution, or in a disposable version, to obtain a new device
10. At this first low level point, however, the drug solution may
not be sufficiently low to be disabled, and will continue to
function. At a second low level point (e.g., when the drug solution
62 is of a less than desirable thermal mass) the system control
electronics 380 will then disable the aerosol generator. In such a
dual level detection arrangement, it is contemplated that the
control electronics can sense two different current levels
transmitted through the drug solution 62, as the current level
decreases with the increased resistance due to drug solution
depletion. In another embodiment, two different probes are provided
for detecting the two different drug levels.
It should also be appreciated that many of the principles of the
present invention can be employed without a level detector, or with
a known, conventional level detector.
It should also be appreciated that many of the principles of the
present invention can be applied to a dual system that employs more
than one aerosol generator 66. This may be useful again where high
viscosity drug solution is being used, in order to increase the
amount of drug that can be delivered. This dual arrangement is also
disclosed in the aforementioned U.S. patent application Ser. No.
60/659,919 has been incorporated by reference.
It can thus be appreciated that embodiments of the present
invention have now been fully and effectively accomplished. The
foregoing embodiments have been provided to illustrate the
structural and functional principles of the present invention, and
are not intended to be limiting. To the contrary, the present
invention is intended to encompass all modifications, alterations
and substitutions within the spirit and scope of the appended
claims.
Although the invention has been described in detail for the purpose
of illustration based on what is currently considered to be the
most practical and preferred embodiments, it is to be understood
that such detail is solely for that purpose and that the invention
is not limited to the disclosed embodiments, but, on the contrary,
is intended to cover modifications and equivalent arrangements that
are within the spirit and scope of the appended claims.
* * * * *